The present invention relates generally to surgical micro-cutting instruments. More particularly, it relates to a surgical micro-resecting instrument integrating both mechanical and electrical current cutting.
Surgical cutting instruments in which an elongate inner member is rotated within an elongate outer tubular member have become well accepted in surgical procedures where access to the surgical site is gained via a narrow portal or passage. Typically, the outer tubular member includes a distal end with an opening defining a cutting port or window, and the inner member includes a distal end forming a cutting tip for cutting bodily tissue at the window. Proximal ends of the inner and outer members are commonly secured to hubs that, in turn, are attached to a powered handpiece for rotating and/or oscillating the inner member relative to the outer tubular member. The cutting tip of the inner member can have various configurations specific to the surgical procedure in question (e.g., cutting, resecting, abrading, shaving, etc.), with the cutting window being suitably configured to cooperate with the particular configuration of the cutting tip. Often, the inner member is tubular so that the loose tissue resulting from a cutting, resecting, or abrading procedure can be aspirated through the hollow lumen of the inner member. With specific reference to ENT (i.e., ear, nose, and throat) applications, such as ethmoidectomy, sinus surgery, adenoidectomy, laryngeal surgery, etc., extremely sharp, micro-resecting blades or cutting tips are typically employed to effectuate the desired procedure.
The above-described surgical instruments rely upon a mechanical cutting action to resect, cut, shave, abrade, etc. the tissue in question. With respect to ENT procedures, mechanical-type, micro-resecting instruments are highly viable, and present distinct advantages over other available devices. For example, CO2 lasers are available. However, laser-based systems are expensive and present the distinct risk of thermal trauma or burns.
Efforts have been made to improve upon the design of surgical micro-resecting instruments. For example, the blade or cutting tip configuration can be optimized for certain applications. Further, so as to facilitate access to certain bodily areas, the surgical cutting instrument has been modified from a generally straight form to one having a fixed- or variable-angle design.
Often times, during an ENT micro-resecting procedure, it is necessary to coagulate or otherwise stem bleeding at the target site to provide homostasis. The accepted technique for effectuating homostasis is to remove the micro-resecting instrument and deploy a suction coagulation device. While necessary, this technique is highly time consuming.
Surgical micro-resecting blade instruments continue to be extremely useful. However, a separate device is still required to achieve homostasis at the surgical site. Therefore, a need exists for a single surgical micro-resecting instrument capable of resecting tissue and provide homostasis.
One aspect of the present invention provides a surgical micro-resecting instrument including an outer tubular member, an inner tubular member, a hub assembly, wiring, and an electrical insulator. The outer tubular member is formed of an electrically conductive material and defines a proximal section, an intermediate section, a distal section, and an internal lumen. Further, the distal section forms a cutting window that is otherwise open to the lumen. The inner tubular member is disposed within the lumen and defines a proximal end and a distal end. In this regard, the distal end forms a cutting tip. The hub assembly maintains the outer tubular member at the proximal section thereof, and the inner tubular member at the proximal end thereof. The wiring is permanently, electrically connected to the proximal section of the outer tubular member. Additionally, the wiring is adapted to deliver energy to the outer tubular member from a remote power source. In this regard, the electrical connection of the wiring to the outer tubular member is encompassed by the hub assembly. Finally, the electrical insulator covers a region of the outer tubular member distal the hub assembly. More particularly, at least the cutting window is free of the insulator. With this configuration, the cutting tip is available for resecting tissue. When necessary, an electrical current is applied to the proximal section of the outer tubular member via the wiring. The insulator insulates the outer tubular member along the intermediate section and at least a portion of the distal section, thereby providing an electrode surface area at the exposed portion thereof. As a result, the exposed portion of the distal section cauterizes contacted tissue via the energy to achieve homostasis. In one preferred embodiment, the insulator is a dielectric material coated onto the outer tubular member. In another preferred embodiment, the hub assembly includes an outer hub insert molded to the outer tubular member, and forms a generally radially extending shroud.
Yet another aspect of the present invention relates to a surgical micro-resecting system for use in ENT procedures. The system includes a micro-resecting instrument, a powered surgical handpiece, and an energy source. The micro-resecting instrument includes an outer tubular member, an inner tubular member, a hub assembly, wiring, and an electrical insulator. The outer tubular member is formed of an electrically conductive material and includes a distal section and an internal lumen, with the distal section forming a cutting window otherwise open to the lumen. The inner tubular member is disposed within the lumen of the outer tubular member and defines a distal end forming a cutting tip. The hub assembly is connected to, and maintains, the outer tubular member and the inner tubular member. The wiring is permanently electrically connected to the proximal section of the outer tubular member, with the connection between the wiring and the outer tubular member being encompassed by the hub assembly. Finally, the electrical insulator covers a region of the outer tubular member distal the hub assembly, with at least the cutting window being free of the insulator. The powered surgical handpiece is coupled to a proximal end of the inner tubular member and is configured to drive the inner tubular member relative to the outer tubular member as part of a micro-resecting procedure. Finally, the energy source is electrically connected to the wiring opposite the outer tubular member. With this configuration, activation of the powered surgical handpiece initiates resecting of tissue. Additionally, activation of the energy source effectuates tissue cauterization via delivery of energy to the region of the outer tubular member not otherwise covered by the insulator. In one preferred embodiment, the powered surgical handpiece and the energy source are operated by switching devices located remote of the micro-resecting instrument.
Yet another aspect of the present invention relates to a method for performing a micro-resecting operation at a target site of a patient as part of an ENT surgical procedure. The method includes providing a micro-resecting instrument including an outer tubular member, an inner tubular member, wiring, a hub assembly, and an electrical insulator. The outer tubular member has a lumen and a distal section forming a cutting window otherwise open to the lumen. The inner tubular member is disposed within the lumen and has a distal end forming a cutting tip. The wiring is permanently electrically connected to a proximal section of the outer tubular member at a connection point. The hub assembly is connected to, and maintains, the inner and outer tubular members and envelops the connection point. The electrical insulator covers a region of the outer tubular member distal the hub assembly, such that at least the cutting window remains exposed relative to the insulator. The distal section of the outer tubular member is delivered to the target site such that the cutting window is located at the target site and the cutting tip is located within the cutting window. The inner tubular member is driven relative to the outer tubular member such that the cutting tip resects tissue at the target site to effectuate a portion of an ENT procedure. Energy is applied to an exposed region of the outer tubular member via the wiring. Finally, tissue at the target site is cauterized via the energized exposed region of the outer tubular member.
Yet another aspect of the present invention relates to a method of manufacturing a micro-resecting instrument for use in ENT procedures. The method includes providing an outer tubular member formed of an electrically conductive material and including a proximal section, a distal section, and a lumen. In this regard, the distal section is formed to include a cutting window open to the lumen. An inner tubular member is also provided. The inner tubular member has a proximal end and a distal end, with the distal end forming a cutting tip. The inner tubular member is disposed within the lumen of the outer tubular member such that the cutting tip is aligned with the cutting window. Wiring is electrically connected to the proximal section of the outer tubular member. A hub assembly is connected to the proximal section of the outer tubular member and the proximal end of the inner tubular member. In this regard, the hub assembly is positioned to encompass the connection between the wiring and the outer tubular member such that the wiring is permanently, electrically connected to the outer tubular member. Finally, a region of the outer tubular member distal the hub assembly is covered with an electrical insulator. In this regard, at least the cutting window remains exposed relative to the insulator. In one preferred embodiment, the method further includes providing the hub assembly to include an inner hub for connection to the inner tubular member and an outer hub for connection to the outer tubular member, with the outer hub being insert molded to the outer tubular member.